Foams such as open-celled polyurethane flexible foams, partially open-celled polyurethane flexible foams, latex foams and melamine foams typically have low thermal conductivities in the range of 0.02-0.04 W/m ° K. Materials with low thermal conductivities typically function as insulators, such as rigid polyurethane foam insulation board or expanded polystyrene insulation boards used for insulating purposes.
Heat transfer consists of a combination of conduction, convection and radiation. In a cushion or mattress, heat transfer by radiation is not very large. Instead, heat transfer by conduction and convection are the primary paths for moving heat in a cushion or mattress. As a person sleeps on a mattress, the compressed foam underneath the body has reduced air flow paths, and the primary mode in the region below the body is conduction.
Heat is conducted from the body, through the compressed foam, into one or more foam layers and dispersed through the foam layers into cushion or mattress regions where the foam is not compressed as much, which allows natural convection to occur more readily for removal of heat from the mattress.
Chen disclosed in U.S. Pat. No. 5,760,117 gelatinous composition and articles where the articles from composites, either in non-sticking oriented or non-oriented configuration, including GMG, MGM, MG1G2M, M1M2G1G2, M2M1G1G2, G1MG1G2, MG1G2, G1G2M, G2G1M, GM1M2G, G1M1G2M2M1, M1GM2GM3GM4, etc., where G=gel and M=material. The subscripts 1, 2, 3, 4, etc., are different and are represented by n which is a positive number, when n is a subscript of M, n may be the same or different material and when n is a subscript of G, n can be the same or different rigidity, non-sticking oriented or non-oriented gel or the same or different gel material composition. The material (M) suitable for forming composite articles with the gelatinous elastomer compositions can include foam, plastic, fabric, metal, concrete, wood, wire screen, refractory material, glass, synthetic resin, synthetic fibers, and the like. The non-sticking oriented or non-oriented gel compositions of Chen's disclosure can be casted unto various substrates, such as open cell materials, metals, ceramics, glasses, and plastics, etc.; the molten gel composition is deformed as it is being cooled. Such deformation before being cooled may force molten gel into open-celled materials, such as open-celled polyurethane foam, and open up pathways for air migration through the gel layer. Chen does not mention porous gel layer/flexible cellular foam combination.
St. Clair disclosed in U.S. Pat. No. 6,987,142 a pressure sensitive adhesive composition comprising 100 parts by weight of at least one hydrogenated block copolymer, about 25 to about 300 parts by weight of a compatible styrene/isoprene unhydrogenated block copolymer, about 25 to about 300 parts by weight of at least one tackifying resin and about zero to about 200 parts by weight of an extending oil, wherein said hydrogenated block copolymer has at least one polymer block A and at least one polymer block B, and wherein: a. prior to hydrogenation each A block is a mono alkenyl arene homopolymer block and each B block is a controlled distribution copolymer block of at least one conjugated diene and at least one mono alkenyl arene; b. subsequent to hydrogenation about 0-10% of the arene double bonds have been reduced, and at least about 90% of the conjugated diene double bonds have been reduced; c. each A block having a number average molecular weight between about 3,000 and about 60,000 and each B block having a number average molecular weight between about 20,000 and about 300,000; d. each B block comprises terminal regions adjacent to the A blocks that are rich in conjugated diene units and one or more regions not adjacent to the A blocks that are rich in mono alkenyl arene units; e. the total amount of mono alkenyl arene in the hydrogenated block copolymer is about 20 percent weight to about 80 percent weight; and f. the weight percent of mono alkenyl arene in each B block is between about 10 percent and about 75 percent. Also, St. Clair discloses a solvent-based pressure sensitive adhesive composition wherein the solvent is an aromatic hydrocarbon solvent and a compatible solvent is selected from a group consisting of aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, polar solvents and mixtures thereof. Parachlorobenzotrifluoride (PCBTF) is mentioned in example 9 as an exempt VOC solvent that can be used for replacing at least a portion of toluene in solvating SEBS. However, St. Clair only concerns a pressure sensitive adhesive and does not relate to any cushion foams or mattresses.
There remains a need to improve infusion of flexible foams with a gel, and in particular to improve the thermal conductivity of flexible foams, particularly open-celled polyether polyurethane foam, partially open-celled polyether polyurethane foam, reticulated polyurethane foam, high-resiliency polyether polyurethane foam, open-celled viscoelastic polyether polyurethane foam, partially open-celled viscoelastic polyether polyurethane foam, open-celled polyester polyurethane foam, partially open-celled polyester polyurethane foam, open-celled polyester foam, partially open-celled polyester foam, latex foam, melamine foam, and combinations thereof.